1. Field of the Invention
The present invention relates to recording apparatuses (e.g., ink-jet recording apparatuses) for recording (e.g., forming images) using recording heads, and relates to methods for controlling the apparatuses.
2. Description of the Related Art
Mechanisms such as ink-jet recording apparatuses that convey sheets usually include line feed (LF) rollers (conveying rollers) and eject rollers. When the mechanisms convey sheets, the LF rollers are used as main conveying units and the eject rollers are used as auxiliary conveying units.
The LF rollers are disposed upstream in a direction in which sheets are conveyed (conveying direction), and the eject rollers are disposed downstream in the conveying direction. Recording heads scan over areas between the LF rollers and the eject rollers. Therefore, areas corresponding to areas scanned by the recording heads while the sheets are engaged by the LF rollers and the eject rollers are referred to as “recording areas”.
Furthermore, areas corresponding to areas scanned by the recording heads while the sheets are engaged by only the eject rollers are also referred to as “recording areas”. That is, a recording is also made in areas adjacent to the trailing ends of the sheets.
In order to make up for a reduction in conveying accuracy during recording of the trailing ends of the sheets, a technology described in Japanese Patent Laid-Open No. 2004-230817 reduces the number of nozzles of a recording head to be used and the conveying amount of a sheet per scan when a recording is made in areas adjacent to the trailing ends of the sheet.
FIG. 9 illustrates the positional relationship among a conveying roller 136, a pinch roller 137, and the trailing end of a sheet. In FIG. 9, the sheet is fed from right to left. Each arrow indicates a conveying operation. The end points of the arrows indicate the positions of the trailing end of the sheet after the conveying operations, and the start points of the arrows indicate the positions of the trailing end of the sheet before the conveying operations. An area between A and B shown in FIG. 9 is referred to as an “unstable stop area” where the position of the trailing end of a sheet that has stopped in this area is not stabilized. FIG. 9 illustrates two types of conveying sequences. In Sequence (1), the sheet is conveyed by a conveying amount of P/8 in areas other than the unstable stop area. Furthermore, in Sequence (1), the sheet is conveyed by a conveying amount of 3P/8 such that the trailing end of the sheet does not stop in the unstable stop area. In Sequence (2), the sheet is conveyed by a conveying amount of P/8 in all areas. In this case, the trailing end of the sheet stops in the unstable stop area two times.
In Sequence (1), the conveying amount per conveying operation is small. This leads to increases in the number of times scanning is performed by the recording head and in the number of conveying operations, resulting in a reduction in throughput in recording operations.
In Sequence (2), the trailing end of the sheet stops in the unstable stop area two times. Therefore, the conveying amount in the unstable stop area becomes different from that in areas other than the unstable stop area, resulting in a reduction in image quality.